Thermostat.



C. J. FOX.

THERMOSTAT. APPLIUATIOI FILED JAN. 28, 1907'.

PATENTED MAR.l 24,1908.

CHARLES JAMES FOX, OELONDON,

THERMOSTAT Original applitation led April 3, 1906, Serial Specification of Letters` Patent.

s PATENT oEEroE.

EN GLAND.

Patented March 24, 1908.

No. 309,603. Divided and this application filed January 28, 190'?.I

Serial No. 354,531.

To all 'whom it may concern:

Be it known that 1, CHAELEs JAMES Fox, a subject ot the King of Great Britain, and a resident 'formerly of 64 VVatling street, in the |l city oiiliondon, and now of 11 Queen'Street Place, in the city oi London, England, lieutenant colonel, have invented an Improved Thermostat, ot which the .following ,is a speciiication, this being a division ot the application 'lor Letters Patent for an improvement in automatic 'lire-alarm systems tiled by me April 3, 1906, Serial No. 309,603.

The object ot this invention is to provide an improved thermostat adapted to be interposed in an electric circuit containing a visual or auditory alarm, whereby notice will be given when the electric circuit is closed by the thermostat on a predetermined temperature being attained.

The thermostat oi' my invention comprises horizontally disposed strips oi' metal adapted by their expansion in the presence oi high temperatures to sag and thereby make contact with terminals, thus closing the alarm circuit, the temperature at which contact is to be made being determined by the position ot the terminals, which are made adjustable so that the instrument may be set to operate at any desired temperature.

Referring to the accompanying drawings 'forming part of this speci'lication, Figure 1 illustrates the improved thermostat and electric connections lior giving an audible 2 shows a three-way Jiorm signal, while Fig. of the thermostat provided with two independent strips oi' metal.

On a base a is mounted a metal frame t, across which a horizontal strip c oi metal is stretched and secured so that, when exanded by heat it will sag downwards from its norm al position and, upon the rise of temperature producing a predetermined. deflection ol the strip, the latter will come in contact with a terminal d, and complete the electric circuit through the lead e connected with the terminal d and the lead f connected with the frame b.

rlhe terminal d which consists oic a set screw, is carried on the base c by an insulating support g, adjusted relatively to the level of the strip and locked in position by means l ot nuts h, such Aadjustment enabling the amount oi' deflection oi the strip to be dewhen the circuit is lpole oi an termined. which is requisite to close the circuit at and therefore determining the temperature at which the alarm will be set in operation.

The thermostat shown in Fig. 2 is similar to that shown in Fig. l, except that two strips c of metal are employed, each secured between pillars andthe ends oi the trame l), and two terminals d corresponding to the two strips and mounted in position on the base a. The three-way connections shown in Fig. 2 consists of the common return lead 7c connected to the trame b and the two leads e connected with the terminal.

Claims. i

'1. A thermostat comprising a non-metallic base, an approximately U-shaped metal 'frame on the base and connected to one pole ot an electric circuit, a horizontally disposed straight strip of metal stretched between the members oi the trame and adapted to sag downwards, when expanded by heat, an adjustable screw terminal connected to the other pole of the electric circuit and with which the metal strip is adapted to make contact, an insulator support carried by the base and in which the screw is mounted, nuts on the screw, one on each side of the support, for adjust-ing and locking the terminal in position, a battery interposed in the electriccircuit and capable oi sending a current through said circuit when the latter is closed by contact oi the metal strip with the adjustable terminal, and an alarm interposed in the circuit and capable ot being set in operation traversed by a current, substantially as specified.

2. A thermostat comprising base, an approximately U- haped metall frame, on the base and connected with one electric circuit, pillars arrange between the members of the iframe and in alincment with the ends thereoi', a plurality of horizontally disposed straight strips of metal. stretched across between the ends ot the frame and the pillars and adapted to sag downwards, when expanded'by heat, a plurality oi adjustable screwterminals connected to the other pole ot the electric circuits an with which the metal strips are adapted to make contact, insulator supports carried by thebase and in which the screws are mounted,

a non-met allie means for adjusting and locking the terminals on the insulator supports, a battery interposed in the electric circuit and connected with a metal frame and capable of sending a current through any of the circuits When the stantially as specified. latter are closed by contact ofthe metal Witnesses:

of being set in operation when any of the circuits are traversed by a current, sub- CHARLES JAMES FOX.

strips With the adJustable terminals, and H. D. JAMESQN, alarms interposed in the circuits and capable A. NUTTING. 

